diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-12-05 17:01:20 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2025-12-05 17:01:20 -0800 |
| commit | 51d90a15fedf8366cb96ef68d0ea2d0bf15417d2 (patch) | |
| tree | f211728418ec63471fcc0c37058326e678808ac0 /arch/x86/kvm/mmu | |
| parent | 399ead3a6d76cbdd29a716660db5c84a314dab70 (diff) | |
| parent | e0c26d47def7382d7dbd9cad58bc653aed75737a (diff) | |
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"ARM:
- Support for userspace handling of synchronous external aborts
(SEAs), allowing the VMM to potentially handle the abort in a
non-fatal manner
- Large rework of the VGIC's list register handling with the goal of
supporting more active/pending IRQs than available list registers
in hardware. In addition, the VGIC now supports EOImode==1 style
deactivations for IRQs which may occur on a separate vCPU than the
one that acked the IRQ
- Support for FEAT_XNX (user / privileged execute permissions) and
FEAT_HAF (hardware update to the Access Flag) in the software page
table walkers and shadow MMU
- Allow page table destruction to reschedule, fixing long
need_resched latencies observed when destroying a large VM
- Minor fixes to KVM and selftests
Loongarch:
- Get VM PMU capability from HW GCFG register
- Add AVEC basic support
- Use 64-bit register definition for EIOINTC
- Add KVM timer test cases for tools/selftests
RISC/V:
- SBI message passing (MPXY) support for KVM guest
- Give a new, more specific error subcode for the case when in-kernel
AIA virtualization fails to allocate IMSIC VS-file
- Support KVM_DIRTY_LOG_INITIALLY_SET, enabling dirty log gradually
in small chunks
- Fix guest page fault within HLV* instructions
- Flush VS-stage TLB after VCPU migration for Andes cores
s390:
- Always allocate ESCA (Extended System Control Area), instead of
starting with the basic SCA and converting to ESCA with the
addition of the 65th vCPU. The price is increased number of exits
(and worse performance) on z10 and earlier processor; ESCA was
introduced by z114/z196 in 2010
- VIRT_XFER_TO_GUEST_WORK support
- Operation exception forwarding support
- Cleanups
x86:
- Skip the costly "zap all SPTEs" on an MMIO generation wrap if MMIO
SPTE caching is disabled, as there can't be any relevant SPTEs to
zap
- Relocate a misplaced export
- Fix an async #PF bug where KVM would clear the completion queue
when the guest transitioned in and out of paging mode, e.g. when
handling an SMI and then returning to paged mode via RSM
- Leave KVM's user-return notifier registered even when disabling
virtualization, as long as kvm.ko is loaded. On reboot/shutdown,
keeping the notifier registered is ok; the kernel does not use the
MSRs and the callback will run cleanly and restore host MSRs if the
CPU manages to return to userspace before the system goes down
- Use the checked version of {get,put}_user()
- Fix a long-lurking bug where KVM's lack of catch-up logic for
periodic APIC timers can result in a hard lockup in the host
- Revert the periodic kvmclock sync logic now that KVM doesn't use a
clocksource that's subject to NTP corrections
- Clean up KVM's handling of MMIO Stale Data and L1TF, and bury the
latter behind CONFIG_CPU_MITIGATIONS
- Context switch XCR0, XSS, and PKRU outside of the entry/exit fast
path; the only reason they were handled in the fast path was to
paper of a bug in the core #MC code, and that has long since been
fixed
- Add emulator support for AVX MOV instructions, to play nice with
emulated devices whose guest drivers like to access PCI BARs with
large multi-byte instructions
x86 (AMD):
- Fix a few missing "VMCB dirty" bugs
- Fix the worst of KVM's lack of EFER.LMSLE emulation
- Add AVIC support for addressing 4k vCPUs in x2AVIC mode
- Fix incorrect handling of selective CR0 writes when checking
intercepts during emulation of L2 instructions
- Fix a currently-benign bug where KVM would clobber SPEC_CTRL[63:32]
on VMRUN and #VMEXIT
- Fix a bug where KVM corrupt the guest code stream when re-injecting
a soft interrupt if the guest patched the underlying code after the
VM-Exit, e.g. when Linux patches code with a temporary INT3
- Add KVM_X86_SNP_POLICY_BITS to advertise supported SNP policy bits
to userspace, and extend KVM "support" to all policy bits that
don't require any actual support from KVM
x86 (Intel):
- Use the root role from kvm_mmu_page to construct EPTPs instead of
the current vCPU state, partly as worthwhile cleanup, but mostly to
pave the way for tracking per-root TLB flushes, and elide EPT
flushes on pCPU migration if the root is clean from a previous
flush
- Add a few missing nested consistency checks
- Rip out support for doing "early" consistency checks via hardware
as the functionality hasn't been used in years and is no longer
useful in general; replace it with an off-by-default module param
to WARN if hardware fails a check that KVM does not perform
- Fix a currently-benign bug where KVM would drop the guest's
SPEC_CTRL[63:32] on VM-Enter
- Misc cleanups
- Overhaul the TDX code to address systemic races where KVM (acting
on behalf of userspace) could inadvertantly trigger lock contention
in the TDX-Module; KVM was either working around these in weird,
ugly ways, or was simply oblivious to them (though even Yan's
devilish selftests could only break individual VMs, not the host
kernel)
- Fix a bug where KVM could corrupt a vCPU's cpu_list when freeing a
TDX vCPU, if creating said vCPU failed partway through
- Fix a few sparse warnings (bad annotation, 0 != NULL)
- Use struct_size() to simplify copying TDX capabilities to userspace
- Fix a bug where TDX would effectively corrupt user-return MSR
values if the TDX Module rejects VP.ENTER and thus doesn't clobber
host MSRs as expected
Selftests:
- Fix a math goof in mmu_stress_test when running on a single-CPU
system/VM
- Forcefully override ARCH from x86_64 to x86 to play nice with
specifying ARCH=x86_64 on the command line
- Extend a bunch of nested VMX to validate nested SVM as well
- Add support for LA57 in the core VM_MODE_xxx macro, and add a test
to verify KVM can save/restore nested VMX state when L1 is using
5-level paging, but L2 is not
- Clean up the guest paging code in anticipation of sharing the core
logic for nested EPT and nested NPT
guest_memfd:
- Add NUMA mempolicy support for guest_memfd, and clean up a variety
of rough edges in guest_memfd along the way
- Define a CLASS to automatically handle get+put when grabbing a
guest_memfd from a memslot to make it harder to leak references
- Enhance KVM selftests to make it easer to develop and debug
selftests like those added for guest_memfd NUMA support, e.g. where
test and/or KVM bugs often result in hard-to-debug SIGBUS errors
- Misc cleanups
Generic:
- Use the recently-added WQ_PERCPU when creating the per-CPU
workqueue for irqfd cleanup
- Fix a goof in the dirty ring documentation
- Fix choice of target for directed yield across different calls to
kvm_vcpu_on_spin(); the function was always starting from the first
vCPU instead of continuing the round-robin search"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (260 commits)
KVM: arm64: at: Update AF on software walk only if VM has FEAT_HAFDBS
KVM: arm64: at: Use correct HA bit in TCR_EL2 when regime is EL2
KVM: arm64: Document KVM_PGTABLE_PROT_{UX,PX}
KVM: arm64: Fix spelling mistake "Unexpeced" -> "Unexpected"
KVM: arm64: Add break to default case in kvm_pgtable_stage2_pte_prot()
KVM: arm64: Add endian casting to kvm_swap_s[12]_desc()
KVM: arm64: Fix compilation when CONFIG_ARM64_USE_LSE_ATOMICS=n
KVM: arm64: selftests: Add test for AT emulation
KVM: arm64: nv: Expose hardware access flag management to NV guests
KVM: arm64: nv: Implement HW access flag management in stage-2 SW PTW
KVM: arm64: Implement HW access flag management in stage-1 SW PTW
KVM: arm64: Propagate PTW errors up to AT emulation
KVM: arm64: Add helper for swapping guest descriptor
KVM: arm64: nv: Use pgtable definitions in stage-2 walk
KVM: arm64: Handle endianness in read helper for emulated PTW
KVM: arm64: nv: Stop passing vCPU through void ptr in S2 PTW
KVM: arm64: Call helper for reading descriptors directly
KVM: arm64: nv: Advertise support for FEAT_XNX
KVM: arm64: Teach ptdump about FEAT_XNX permissions
KVM: s390: Use generic VIRT_XFER_TO_GUEST_WORK functions
...
Diffstat (limited to 'arch/x86/kvm/mmu')
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 94 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/mmu_internal.h | 10 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/paging_tmpl.h | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/spte.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/spte.h | 10 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/tdp_mmu.c | 50 |
6 files changed, 110 insertions, 58 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 667d66cf76d5..02c450686b4a 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4859,7 +4859,7 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, */ BUILD_BUG_ON(lower_32_bits(PFERR_SYNTHETIC_MASK)); - vcpu->arch.l1tf_flush_l1d = true; + kvm_request_l1tf_flush_l1d(); if (!flags) { trace_kvm_page_fault(vcpu, fault_address, error_code); @@ -4924,7 +4924,8 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) return direct_page_fault(vcpu, fault); } -int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code, u8 *level) +static int kvm_tdp_page_prefault(struct kvm_vcpu *vcpu, gpa_t gpa, + u64 error_code, u8 *level) { int r; @@ -4966,7 +4967,6 @@ int kvm_tdp_map_page(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code, u8 *level return -EIO; } } -EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_tdp_map_page); long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu, struct kvm_pre_fault_memory *range) @@ -5002,7 +5002,7 @@ long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu, * Shadow paging uses GVA for kvm page fault, so restrict to * two-dimensional paging. */ - r = kvm_tdp_map_page(vcpu, range->gpa | direct_bits, error_code, &level); + r = kvm_tdp_page_prefault(vcpu, range->gpa | direct_bits, error_code, &level); if (r < 0) return r; @@ -5014,6 +5014,86 @@ long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu, return min(range->size, end - range->gpa); } +#ifdef CONFIG_KVM_GUEST_MEMFD +static void kvm_assert_gmem_invalidate_lock_held(struct kvm_memory_slot *slot) +{ +#ifdef CONFIG_PROVE_LOCKING + if (WARN_ON_ONCE(!kvm_slot_has_gmem(slot)) || + WARN_ON_ONCE(!slot->gmem.file) || + WARN_ON_ONCE(!file_count(slot->gmem.file))) + return; + + lockdep_assert_held(&file_inode(slot->gmem.file)->i_mapping->invalidate_lock); +#endif +} + +int kvm_tdp_mmu_map_private_pfn(struct kvm_vcpu *vcpu, gfn_t gfn, kvm_pfn_t pfn) +{ + struct kvm_page_fault fault = { + .addr = gfn_to_gpa(gfn), + .error_code = PFERR_GUEST_FINAL_MASK | PFERR_PRIVATE_ACCESS, + .prefetch = true, + .is_tdp = true, + .nx_huge_page_workaround_enabled = is_nx_huge_page_enabled(vcpu->kvm), + + .max_level = PG_LEVEL_4K, + .req_level = PG_LEVEL_4K, + .goal_level = PG_LEVEL_4K, + .is_private = true, + + .gfn = gfn, + .slot = kvm_vcpu_gfn_to_memslot(vcpu, gfn), + .pfn = pfn, + .map_writable = true, + }; + struct kvm *kvm = vcpu->kvm; + int r; + + lockdep_assert_held(&kvm->slots_lock); + + /* + * Mapping a pre-determined private pfn is intended only for use when + * populating a guest_memfd instance. Assert that the slot is backed + * by guest_memfd and that the gmem instance's invalidate_lock is held. + */ + kvm_assert_gmem_invalidate_lock_held(fault.slot); + + if (KVM_BUG_ON(!tdp_mmu_enabled, kvm)) + return -EIO; + + if (kvm_gfn_is_write_tracked(kvm, fault.slot, fault.gfn)) + return -EPERM; + + r = kvm_mmu_reload(vcpu); + if (r) + return r; + + r = mmu_topup_memory_caches(vcpu, false); + if (r) + return r; + + do { + if (signal_pending(current)) + return -EINTR; + + if (kvm_test_request(KVM_REQ_VM_DEAD, vcpu)) + return -EIO; + + cond_resched(); + + guard(read_lock)(&kvm->mmu_lock); + + r = kvm_tdp_mmu_map(vcpu, &fault); + } while (r == RET_PF_RETRY); + + if (r != RET_PF_FIXED) + return -EIO; + + return 0; +} +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_tdp_mmu_map_private_pfn); +#endif + static void nonpaging_init_context(struct kvm_mmu *context) { context->page_fault = nonpaging_page_fault; @@ -5997,7 +6077,6 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu) out: return r; } -EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_mmu_load); void kvm_mmu_unload(struct kvm_vcpu *vcpu) { @@ -6863,6 +6942,7 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) write_unlock(&kvm->mmu_lock); } +EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_zap_gfn_range); static bool slot_rmap_write_protect(struct kvm *kvm, struct kvm_rmap_head *rmap_head, @@ -7204,7 +7284,6 @@ restart: return need_tlb_flush; } -EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_zap_gfn_range); static void kvm_rmap_zap_collapsible_sptes(struct kvm *kvm, const struct kvm_memory_slot *slot) @@ -7364,6 +7443,9 @@ void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen) { WARN_ON_ONCE(gen & KVM_MEMSLOT_GEN_UPDATE_IN_PROGRESS); + if (!enable_mmio_caching) + return; + gen &= MMIO_SPTE_GEN_MASK; /* diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index ed5c01df21ba..73cdcbccc89e 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -39,16 +39,6 @@ #define INVALID_PAE_ROOT 0 #define IS_VALID_PAE_ROOT(x) (!!(x)) -static inline hpa_t kvm_mmu_get_dummy_root(void) -{ - return my_zero_pfn(0) << PAGE_SHIFT; -} - -static inline bool kvm_mmu_is_dummy_root(hpa_t shadow_page) -{ - return is_zero_pfn(shadow_page >> PAGE_SHIFT); -} - typedef u64 __rcu *tdp_ptep_t; struct kvm_mmu_page { diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index ed762bb4b007..901cd2bd40b8 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -402,7 +402,7 @@ retry_walk: goto error; ptep_user = (pt_element_t __user *)((void *)host_addr + offset); - if (unlikely(__get_user(pte, ptep_user))) + if (unlikely(get_user(pte, ptep_user))) goto error; walker->ptep_user[walker->level - 1] = ptep_user; diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index 37647afde7d3..85a0473809b0 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c @@ -292,7 +292,7 @@ bool make_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, mark_page_dirty_in_slot(vcpu->kvm, slot, gfn); } - if (static_branch_unlikely(&cpu_buf_vm_clear) && + if (cpu_feature_enabled(X86_FEATURE_CLEAR_CPU_BUF_VM_MMIO) && !kvm_vcpu_can_access_host_mmio(vcpu) && kvm_is_mmio_pfn(pfn, &is_host_mmio)) kvm_track_host_mmio_mapping(vcpu); diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h index 3133f066927e..91ce29fd6f1b 100644 --- a/arch/x86/kvm/mmu/spte.h +++ b/arch/x86/kvm/mmu/spte.h @@ -246,6 +246,16 @@ static inline int spte_index(u64 *sptep) */ extern u64 __read_mostly shadow_nonpresent_or_rsvd_lower_gfn_mask; +static inline hpa_t kvm_mmu_get_dummy_root(void) +{ + return my_zero_pfn(0) << PAGE_SHIFT; +} + +static inline bool kvm_mmu_is_dummy_root(hpa_t shadow_page) +{ + return is_zero_pfn(shadow_page >> PAGE_SHIFT); +} + static inline struct kvm_mmu_page *to_shadow_page(hpa_t shadow_page) { struct page *page = pfn_to_page((shadow_page) >> PAGE_SHIFT); diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index c5734ca5c17d..9c26038f6b77 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -362,9 +362,6 @@ static void tdp_mmu_unlink_sp(struct kvm *kvm, struct kvm_mmu_page *sp) static void remove_external_spte(struct kvm *kvm, gfn_t gfn, u64 old_spte, int level) { - kvm_pfn_t old_pfn = spte_to_pfn(old_spte); - int ret; - /* * External (TDX) SPTEs are limited to PG_LEVEL_4K, and external * PTs are removed in a special order, involving free_external_spt(). @@ -377,9 +374,8 @@ static void remove_external_spte(struct kvm *kvm, gfn_t gfn, u64 old_spte, /* Zapping leaf spte is allowed only when write lock is held. */ lockdep_assert_held_write(&kvm->mmu_lock); - /* Because write lock is held, operation should success. */ - ret = kvm_x86_call(remove_external_spte)(kvm, gfn, level, old_pfn); - KVM_BUG_ON(ret, kvm); + + kvm_x86_call(remove_external_spte)(kvm, gfn, level, old_spte); } /** @@ -519,7 +515,6 @@ static int __must_check set_external_spte_present(struct kvm *kvm, tdp_ptep_t sp bool was_present = is_shadow_present_pte(old_spte); bool is_present = is_shadow_present_pte(new_spte); bool is_leaf = is_present && is_last_spte(new_spte, level); - kvm_pfn_t new_pfn = spte_to_pfn(new_spte); int ret = 0; KVM_BUG_ON(was_present, kvm); @@ -538,7 +533,7 @@ static int __must_check set_external_spte_present(struct kvm *kvm, tdp_ptep_t sp * external page table, or leaf. */ if (is_leaf) { - ret = kvm_x86_call(set_external_spte)(kvm, gfn, level, new_pfn); + ret = kvm_x86_call(set_external_spte)(kvm, gfn, level, new_spte); } else { void *external_spt = get_external_spt(gfn, new_spte, level); @@ -1273,6 +1268,8 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault) struct kvm_mmu_page *sp; int ret = RET_PF_RETRY; + KVM_MMU_WARN_ON(!root || root->role.invalid); + kvm_mmu_hugepage_adjust(vcpu, fault); trace_kvm_mmu_spte_requested(fault); @@ -1939,13 +1936,16 @@ bool kvm_tdp_mmu_write_protect_gfn(struct kvm *kvm, * * Must be called between kvm_tdp_mmu_walk_lockless_{begin,end}. */ -static int __kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, - struct kvm_mmu_page *root) +int kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, + int *root_level) { + struct kvm_mmu_page *root = root_to_sp(vcpu->arch.mmu->root.hpa); struct tdp_iter iter; gfn_t gfn = addr >> PAGE_SHIFT; int leaf = -1; + *root_level = vcpu->arch.mmu->root_role.level; + for_each_tdp_pte(iter, vcpu->kvm, root, gfn, gfn + 1) { leaf = iter.level; sptes[leaf] = iter.old_spte; @@ -1954,36 +1954,6 @@ static int __kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, return leaf; } -int kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, - int *root_level) -{ - struct kvm_mmu_page *root = root_to_sp(vcpu->arch.mmu->root.hpa); - *root_level = vcpu->arch.mmu->root_role.level; - - return __kvm_tdp_mmu_get_walk(vcpu, addr, sptes, root); -} - -bool kvm_tdp_mmu_gpa_is_mapped(struct kvm_vcpu *vcpu, u64 gpa) -{ - struct kvm *kvm = vcpu->kvm; - bool is_direct = kvm_is_addr_direct(kvm, gpa); - hpa_t root = is_direct ? vcpu->arch.mmu->root.hpa : - vcpu->arch.mmu->mirror_root_hpa; - u64 sptes[PT64_ROOT_MAX_LEVEL + 1], spte; - int leaf; - - lockdep_assert_held(&kvm->mmu_lock); - rcu_read_lock(); - leaf = __kvm_tdp_mmu_get_walk(vcpu, gpa, sptes, root_to_sp(root)); - rcu_read_unlock(); - if (leaf < 0) - return false; - - spte = sptes[leaf]; - return is_shadow_present_pte(spte) && is_last_spte(spte, leaf); -} -EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_tdp_mmu_gpa_is_mapped); - /* * Returns the last level spte pointer of the shadow page walk for the given * gpa, and sets *spte to the spte value. This spte may be non-preset. If no |